Optical Transparency of Wood and Natural-Fibre Composites

This project is about developing the knowledge-base for achieving optical transparency in solid wood and natural- fibre composites. Semi- or full-transparency for light is seen as a major added-value for these materials, which will help finding new emerging markets, making renewable wood/fibre-based materials more competitive. Applications for transparent materials range from home and office furniture, flooring, decking, exterior cladding, staircases, displays for electronic devices. However, the idea is far from being at the state of developing applications. Many basic questions still need to be solved before one can move on to a next level. The intention of this project is a comprehensive investigation on developing and transferring the theoretical concept to make wood and natural-fibre composites optically transparent, by including transparent media in a way that a refractive continuum is created. This principle will be applied to composites reinforced with plant fibres, to fibrillated cellulose composites, and to solid wood. With laboratory scale as well as prepilot experiments, the outcome of this project will attract future industry partners for R&D efforts towards marketable applications. The project proposal states four major hypotheses and a number of sub-hypotheses that are addressed in a scientific programme of four workpackages. The work ranges from a comparison of dispersion - homogenization methods and raw materials to produce transparent nanofibrillated films having also good mechanical properties; to the morphology and properties of cellulose ester blends, with intensive characterisation and fibre-reinforced composite processing trials; to thermoplastic blends of several biodegradable polymers with lignin and lignin esters that are prepared by solvent casting and melt processing; and finally, to transparent solid wood where a preparation of impregnated wood samples is followed by a characterisation at the cellular level, to fully understand what is driving the optical properties, with impregnation cycles to identify critical processing parameters. A final workpackage is on evaluating and translating the research results, to focus at the end on the commercial evaluation of the findings and transferring the results into commercially viable product ideas. By demonstrating prototype samples to industry and defining criteria that include market situations and costs, decisions are made on how to continue. The goal is to put together a consortium with one or several industry partners that are interested in developing actual applications.

This project is about developing the knowledge-base for achieving optical transparency in solid wood and natural- fibre composites. Semi- or full-transparency for light is seen as a major added-value for these materials, which will help finding new emerging markets, making renewable wood/fibre-based materials more competitive. Applications for transparent materials range from home and office furniture, flooring, decking, exterior cladding, staircases, displays for electronic devices. However, the idea is far from being at the state of developing applications. Many basic questions still need to be solved before one can move on to a next level. The intention of this project is a comprehensive investigation on developing and transferring the theoretical concept to make wood and natural-fibre composites optically transparent, by including transparent media in a way that a "refractive continuum" is created. This principle will be applied to composites reinforced with plant fibres, to fibrillated cellulose composites, and to solid wood. With laboratory scale as well as prepilot experiments, the outcome of this project will attract future industry partners for R&D efforts towards marketable applications. The project proposal states four major hypotheses and a number of sub-hypotheses that are addressed in a scientific programme of four workpackages. The work ranges from a comparison of dispersion - homogenization methods and raw materials to produce transparent nanofibrillated films having also good mechanical properties; to the morphology and properties of cellulose ester blends, with intensive characterisation and fibre-reinforced composite processing trials; to thermoplastic blends of several biodegradable polymers with lignin and lignin esters that are prepared by solvent casting and melt processing; and finally, to transparent solid wood where a preparation of impregnated wood samples is followed by a characterisation at the cellular level, to fully understand what is driving the optical properties, with impregnation cycles to identify critical processing parameters. A final workpackage is on evaluating and translating the research results, to focus at the end on the commercial evaluation of the findings and transferring the results into commercially viable product ideas. By demonstrating prototype samples to industry and defining criteria that include market situations and costs, decisions are made on how to continue. The goal is to put together a consortium with one or several industry partners that are interested in developing actual applications.